Etabs is described as 'For nearly 30 years, ETABS has been recognized as the industry standard for Building Analysis and Design Software. Today, continuing in the same tradition, ETABS has evolved into a completely integrated building analysis and design environment' and is an app. There are more than 25 alternatives to Etabs for Windows, Linux, Mac and Web-based. The best Etabs alternative is Robot Structural Analysis Professional. It's not free, so if you're looking for a free alternative, you could try Estru3D or FRAMEWORK 2D+3D. Other great apps like Etabs are SAP2000, RISA-3D, RAM Elements and midas Civil.